It was Macrow and Blake Purdie that battled for the lead on the opening lap. Macrow made a brilliant start from the second row to grab the lead into the first corner, only for Purdie to slide past at Honda later in the first lap.
Purdie's lead, however, was short-lived, the teenager running wide on the exit of Turn 1 on the second lap before firing off the road on the way into Southern Loop.
That handed the lead back to Macrow who was left roughly half a second ahead of Cooper Webster and Zane Goddard.
From there it became a case of lead management for Macrow as he kept Webster and a hard-charging Mawson at bay across the remainder of the race.
Macrow's final winning margin was just over a second from Webster.
"That was good. The car ran faultlessly," said Macrow.
"We made a couple of little set-up changes. I still think we're got to find a little bit more pace. I held my own there but Cooper was fast and obviously Joey was coming as well. We've got a bit of work to do but we're there or thereabouts."
Mawson charged through the field to finish third after starting on the fourth row of the grid due to the reverse qualifying format.
Race 1 winner James Golding made decent ground too, although only got as far as fifth place behind Goddard.
Shae Davies finished sixth ahead of Kaleb Ngatoa and Adam Harwood.
Purdie, meanwhile, wasn't classified after a puncture took him out of the race a lap after his off.
The second round of the Gold Star series concludes with a feature race at 3:30pm local time tomorrow.
Watch it live and free on Motorsport.tv.
